Residential ventilation - incorrect ceiling installation

Hello everyone,

I have the following problem: We are currently building a single-family house with central ventilation. When pouring the concrete ceiling, the breakthrough or recess for the ventilation pipes was set incorrectly. In other words, the ventilation pipes come out of the ceiling at the wrong spot and now have to be rerouted. My site manager told me that these will now be routed to the correct place via flat ducts in the screed and that this is no problem at all. There are 6 pipes (I believe 70mm) that were routed through the ceiling. I can't quite believe that. The planned floor construction is 19cm including insulation and underfloor heating. What is your assessment of the whole matter? What do I need to pay attention to? Is this permissible? Are there possibly problems with noise due to the change of the pipe system?

I am grateful for any input!

Hello.

In our new building, flat ducts for ventilation were also laid under the screed. That was planned that way. (So it must be a common method) I cannot say whether there could be noise problems, we are still in the rental apartment.

this is our bedroom before insulation and screed

I am grateful for any input!

I do not understand the problem. The breakthroughs have nothing to do with the laying of the pipes. They are in the wrong place. Okay, then they must be closed and a core drilling must be made in the correct place. Questions: What does the structural engineer say now about his perforated ceiling? What does the site manager say about the schedule? The floor structure seems sufficient to me (planned 20 cm here). Watch out for intersections of the ventilation flat duct with electrical and sanitary! Everything must be carried out cleanly and disappear in the insulation layer.

Thanks already for the quick answers!

I also thought that it would be solved that way. That is indeed the case with my recessed spotlights, which were ALSO (!) installed incorrectly and are now being moved using core drilling (same ceiling). However, for the ventilation, they do not want to do core drilling but want to lead the main ducts to the appropriate position using the flat ducts. That makes me suspicious...

To understand this, one would need to see the (ursprüngliche) ventilation plan with the location of the incorrect breakthroughs.

Here is an excerpt from the plan, in green the planned location of the ventilation ducts (ceiling breakthrough) and in red the work carried out. Thank you for the help